Author Topic: 7mm Hayabusa Build (Read 22814 times))

Tofazfou · « **Reply #40 on:** March 08, 2015, 12:45:46 AM »

A few quick pics BOB of the 7mm BBT 95 gr LBT mold:

Some of the bullets from the BBT mold:
The bullets look good but the smooth lube grooves have me wondering if its my pots LOW TEMP or the mold is just that way. A LBT 130 gr FP picture was taken next to the BBT bullet for comparison. Regardless thought, only shooting will tell. Im going to test them out tomorrow.

KnifeMaker · « **Reply #41 on:** March 08, 2015, 05:08:16 AM »

Cedric, it's more than likely the mold temp rather than the pot temp, Folks try to cover up Way too much casting issues by turning up the heat. It's usually only a crutch to cover up something else that is wrong.

Mike

Tofazfou · « **Reply #42 on:** March 08, 2015, 07:09:07 PM »

I will try and heat the mold up more during the casting process and see if i can get some defined lines of the bullets. I don't know though, the lines are hard to see in the mold and i'm casting no different than i usually do.

But again, i will retry everything all over with casting.

dyotat100 · « **Reply #43 on:** March 09, 2015, 01:36:08 AM »

I dropped my mold in the mail to go back. I want .285"-.28550". Plus the the holes were suppose to be .100". Makes for a nice base with the small hole.

rsterne · « **Reply #44 on:** March 09, 2015, 12:24:17 PM »

Erik has already done the conversion and my HP mold is on the way north.... Can't wait !!!

Bob

Tofazfou · « **Reply #45 on:** March 09, 2015, 09:13:45 PM »

Erik IS fast for sure! Always like a 1 week turnaround. I love that dude!

Good for you bob. Post up some pics of the conversion and the weights. I can tell you, there is a big FPS difference between the 130's and the 95's......lol! Love the lightweights

rsterne · « **Reply #46 on:** March 09, 2015, 11:12:31 PM »

Great.... but can you hit anything with them?.... *LOL*....

Bob

Tofazfou · « **Reply #47 on:** March 09, 2015, 11:29:58 PM »

suuuuure i can! 1 Apple and various water filled Coke cans at 205 yards with 1 shot each. After practicing of course but nonetheless............DONE IT on VIDEO!

I hope for better results though once i RECAST all my slugs over again. The bullet is proving to show some serious potential.

rsterne · « **Reply #48 on:** March 10, 2015, 12:06:53 AM »

I'm speechless.... *drool*....

Bob

drewciferpike · « **Reply #49 on:** March 10, 2015, 12:17:18 AM »

Quote from: Tofazfou on March 09, 2015, 11:29:58 PM

DONE IT on VIDEO!

Trust me: You cannot possibly post the vid, soon enough. We're all on the edges of our seats (or even possibly standing)...

Tofazfou · « **Reply #50 on:** March 10, 2015, 01:20:08 AM »

Drew,

Thanks bro. It will be a "few". So much to do, so little time for REAL FUN.......lol! I only made it out to 205 yards on this day. But after i recast, i'm going not only to 200+ yards again but im going somewhere into the 400's (yards that is....) with Bob's bullets along with the 130 gr LBT FNs.

Bob,

On that day, i will also do some close range and far range Chrony shooting so we can get a BC # for these little cute airgun pellets......

rsterne · « **Reply #51 on:** March 10, 2015, 01:23:45 AM »

That will be kewl!.... look forward to it....

Bob

Tofazfou · « **Reply #52 on:** March 11, 2015, 01:33:20 AM »

Bob,

The fastest i've seen the BBT 7mm's tonight is 988.8 fps @ 98.5 grs+-. That's only 214 FPE but i'm much more cool with the speed than the FPE with this gun. Bullets are obviously LIGHT comparted to bigger cals like the 308. But of course, that FPS came from only 3500 psi and i usually fill to 3600 psi.

The 132+ gr LBT FP's are going 100 fps slower @ 882.5 fps off the same fill for 228.3 FPE. I'm cool with that cause its a 250 ft lb gun with 160 gr bullets

rsterne · « **Reply #53 on:** March 11, 2015, 01:51:29 AM »

That's CRANKIN'.... *grin*.... I'll only be running 3000 with my Hayabusa, so anything in the 9's will be nice.... I'm looking forward to hearing what the BCs are for the three different bullets.... 160 gr. in 7mm must be HUGE!!!....

Bob

Tofazfou · « **Reply #54 on:** March 11, 2015, 11:32:46 PM »

Bob,

Sorry, there are cast bullets in 7mm that weight that much but i made a GOOF,

The Corsair in 308 i meant is a 250 FPE gun with 160+ gr bullets.

I did shoot some 160 grs while in SC hunting hogs but boy oh boy, they are too much for my gun.

rsterne · « **Reply #55 on:** March 12, 2015, 01:37:52 AM »

I thought that might be the case.... *LOL*.... would like to see how the BC compares between the BBT and the 132 gr. however....

Bob

Tofazfou · « **Reply #56 on:** March 12, 2015, 02:49:01 PM »

For sure Bob. I will BC both bullets as i too been dying to find that number on the LBT's since i got that mold.

1 bullet that i had was the 7mm 130gr SOUPCAN bullet and its BC was supposed to be roughly .233 at stated by LEE. So the LBT should be by guessing alone, slightly HIGHER than this number for sure. Its OGIVE is waaaay more streamlined than the SOUPCAN. But at least, it should in my OWN theory.....lol! Also hoping yours is much higher than that too with the BT base. Hopefully at least .300..................(fingers crossed)!

The 160 gr 7mm bullet shot out of my gun but the lead was cut for a 130 gr LEE RN bullet. That 160 bullet had a hard time being pushed into the barrels rifling when i closed the bolt probe. BUT THEY SHOT OUT for sure. I tried 3 of them and just QUIT......lol! With a proper LEAD-IN and sizer, they would shoot just fine. If i had the 7mm on a Custom COndor platform then HECK YEAH, it wouldn't be a problem at all and the FPE would be way up there. But i prefer they lighter pills

rsterne · « **Reply #57 on:** March 12, 2015, 03:00:53 PM »

The maximum weight (SD) is directly related to the pressure times barrel length, if you want to get into the 900s.... Sure you can shoot heavier bullets, and they will give you more FPE, but they will be slower.... The only solution is more pressure or a longer barrel.... The 95 gr. weight was chosen based on that is the heaviest I would consider at 3000 psi without going longer than 28-30", which I consider a practical limit.... I figure it will have enough energy to take down anything I would shoot, out as far as I can hit it, so I didn't need more.... The BC is proportional to the SD for any give shape, however, so long heavy bullets can help you reach way out.... Now that Veral has the new nose pattern, he can stretch the length and weight of the 7mm boattail, of course.... Also, he can use his longer ogive existing nose patterns, and my boattail, and produce virtually anything you want.... His system is extremely flexible in that regard.... For example, he could make a mold for that 132 gr. with a boattail very easily.... either with the existing small Meplat, or a slightly larger one.... or right out to a spitzer....

Bob

Tofazfou · « **Reply #58 on:** March 12, 2015, 04:14:41 PM »

Bob,

Thank you for the knowledge on what LBT can do. But i will now say this because of that...............................DARN YOU BOB! DAAAAAARN YOU FOR TELLING ME THAT.................DARN YOOOOOOOOOU!

I dont need another mold.....................................

ok, 1 more maybe (argh, sigh, gasp.....lol)

rsterne · « **Reply #59 on:** March 14, 2015, 04:37:57 PM »

The Carbon Fibre tubing for the shroud came in, and I cut it to length and installed it.... I think it looks quite nice....

In the photo below, the Air Stripper is tightened exactly one turn from when it first contacts the Bellevilles.... That applies 750 lbs. of tension in the barrel (and compression in the shroud).... I plan to leave it under that load for a week and see if the gap in the Bellevilles increases, which would indicate that the CF tubing is compressing over time....

I don't think that the Bellevilles are unattractive at all, in fact in combination with the Stripper it gives quite a unique and purposeful appearance to the muzzle, IMO....

Bob

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7mm Hayabusa Build

Author Topic: 7mm Hayabusa Build (Read 22814 times))